Confused on ad need identification

[u/Benefit_Waste]

Hey all. Just came across this ad. Can anyone identify this shotgun? I thought it was some .22 at first then i fully read eveything. I have never seen or heard about an “hk15” only one i could think of is the deyra mk12

[u/AnthoBMTH]

Is it even legal ? If the answer is yes, i want it,

[u/4r4nd0mninj4 → u/AnthoBMTH]

For now...